Endometriosis Pain, What Causes it?

Most patients who have endometriosis struggle with the breathtaking pain that characterizes the disease. While pain is often associated with endometriosis, the exact reason why endometriosis is painful is not always clear.

Endometriosis is a noxious stimulus, an event that is or can be damaging to the tissues in the body. Physiatrist, Dr. Allyson Shrikhande, describes the tissue damage that occurs from endometriosis as a trauma to the body. It causes the nervous system to be in an excitable state and also starts an inflammatory cascade.

Anesthesiologist, Dr. Gerard DeGregoris, compares the direct invasion of very sensitive structures by endometriosis and the ensuing inflammatory response to getting hit with a hammer. If someone hits you with a hammer, inflammation, a complex biological response of tissues to harmful stimuli, occurs in the form of heat, redness, swelling, and an uncomfortable sensation. In case of trauma to tissues in the body, there is direct stimulation of nerve fibers called nociceptors. When these nerve fibers are stimulated they transmit a pain impulse to the brain. Dr. DeGregoris explains that we developed these pain-filled inflammatory responses so that we can be aware of tissue damage that has occurred in order to try and protect our bodies from harm.

Types of endometriosis pain

Dr. DeGregoris explains how there are two types of pain in endometriosis. These are nociceptor pain and neuropathic pain.

Nociceptor pain is caused by the direct damage of tissue from endometriosis. The sensations associated with this type of pain are usually sharp, aching, or throbbing pains.

Neuropathic pain is another type of pain that endometriosis patients often experience. This pain can occur even after the excision of the disease, as neuropathic pain can last even after inflammation and the direct trauma to the body is no longer there. The sensations associated with neuropathic pain are heavy, stabbing, or burning feelings.

How does excision help reduce endometriosis pain?

Endometriosis excision surgery by an expert doctor is the gold standard of treatment for patients suffering from the disease. Excision removes the disease, or the noxious stimuli, from the body. Dr. Shrikhande works with many endometriosis patients in her practice in New York City.

“I have seen patients pre and post-op of a proper excision treatment. A proper excision surgery gets rid of the noxious stimuli and stops the persistent inflammatory response.”

Some doctors tell their patients that a hysterectomy can cure their endometriosis. If the uterus and ovaries are removed, but endometrial implants are left in the pelvis, these noxious stimuli will continue to cause pain in patients.

Reasons for pain post excision

Unfortunately, some patients who have endometriosis excision, with even the most experienced surgeon, may still experience pain. This can be devastating and confusing to patients. While persistent disease and adhesions from surgery are possible causes of the pain, there are also many other reasons endometriosis patients may experience pain after complete excision.

Patients need to assess whether or not they could have other common co-current conditions that cause pain. Adenomyosis, interstitial cystitis, and pudendal neuralgia are examples of conditions, that endometriosis patients can also have, which often mimic endometriosis pain.

The involvement of the pelvic floor muscles

In her practice, Dr. Shrikhande sees how pelvic floor muscles are intimately involved with the suffering of endometriosis patients. Dr. Shrikhande explains to patients how muscles contract in a linear pattern, kind of like a railroad track. When a patient has a trigger point, the pattern is no longer linear and is in disarray. A trigger point is a palpable taut band of muscle. When you touch the trigger point you get a twitch response and you also may get a referred pain pattern. Physiatrists work in conjunction with pelvic floor therapists to identify trigger points or which muscles in the pelvic floor are causing pain.

Dr. Sallie Sarrel is a pelvic floor therapist that focuses on pelvic pain.

“The cause of pelvic pain is multi-faceted. Even after the disease has been removed pain may remain.”

Dr. Sarrel talks about studies that demonstrate how endometriosis causes higher tone throughout the pelvic floor. A high tone increases the likelihood of painful spasms. She also addresses how the average diagnostic delay of eight to 10 years warps the body and adversely impacts the way the pelvic floor functions. The body forms reactive adaptations to the inflammation, peritoneal insults, adhesions, and constant pain signals caused by endometriosis. Dr. Sarrel has found in her practice that surgery alone cannot always fix these adaptions.

The effect of the diagnostic delay

A diagnostic delay and a delay in having complete excision of endometriosis can transform the acute pain patients experience to chronic pain. Dr. DeGregoris explains that when inflammation goes from acute to chronic, tissues tend to overproduce prostaglandins and an up-regulation of estrogen then maintains chronic inflammation and chronic pain. Dr. Shrikhande discusses how chronic pain can cause allodynia, a condition in which a stimulus that is not usually painful, becomes painful. Chronic pain can also cause hyperalgesia, a condition in which patients experience stimuli as extremely painful that most others find mildly painful. Once pain moves from acute to chronic, the brain stores this pain state and this becomes the patient’s new normal.

Treatment options for endometriosis pain

An anesthesiologist’s perspective

Dr. DeGregoris uses different medications to help both the nociceptor pain and the neuropathic pain that endometriosis patients feel. Most doctors treat patients who present with painful periods with different hormonal treatments, as well as over-the-counter pain medicines. Anti-inflammatory NSAIDs block the conversion and liberation of prostaglandins. Working within one to two hours, the body absorbs NSAIDs well, but too many can cause gastrointestinal issues. Naproxen is also well absorbable but is easier on the stomach. Acetaminophen is the safest pain medication for those patients who are trying to conceive.

The use of opioids to treat pain is controversial. Dr. DeGregoris believes that if opiates are used with the guidance of a physician, they can be safe. He believes they are ideal for postsurgical pain and episodic pain. He stresses that opioids are not ideal for long-term relief because the more a patient takes them, the less pain relief she will get from them. When you take opioids chronically, your body becomes less receptive to their benefits. There are also significant side effects to these drugs such as respiratory depression, hormonal imbalance, opioid-induced constipation, and urinary retention. For some patients who are having worsening pain after opiates, or pain that does not improve, it is worth a try to decrease the dose to see if pain decreases or remains the same.

A physiatrist’s perspective

Dr. Shrikhande uses many different techniques to help endometriosis patients reduce their pain. She finds muscle relaxers (oral or suppository) helpful for patients. For patients with pelvic floor pain, Dr. Shrikhande starts with a suppository made of combined valium and baclofen. She also utilizes ultrasound-guided trigger point injections such as Lidocaine or Traumeel (natural plant-derived product to decrease inflammation). Topical medications made by compounding pharmacies can be quite beneficial to treat patients. Mixtures using Gabapentin or Lyrica, mixed with lidocaine or baclofen or even an NSAID are quite helpful to patients. For patients with vulvodynia, mixing compounds in olive oil reduces irritation.

Dr. Shrikhande not only uses medications but encourages patients to engage in cognitive behavioral therapy, guided imagery, meditation, and lifestyle modification to reduce pain and inflammation. She encourages patients to go to acupuncture to help desensitize the nervous system. She feels that proper breathing techniques can relieve the pressure and pain through the pelvic floor and maybe the fastest way to help. Dr. Shrikhande works hand in hand with pelvic floor therapists to help patients with their lingering pain after surgery.

A pelvic floor therapist’s perspective

Dr. Sallie Sarrel states

“Pain is the sign that something in our bodies is wrong. When you have endometriosis, you have been sending that signal for so many years that your brain is simply overwhelmed. You need to send a different signal and you need to use something to send a different signal. Pelvic physical therapy is one of the things that can mediate that pain signal.”

She stresses that therapists need to have advanced and specialized training beyond doctoral education to evaluate and treat dysfunction of the pelvic floor muscles. Pelvic floor therapists should teach patients postural re-education, muscle relaxation, education for bowel and bladder issues, strengthening exercises, and how to use the body to empower oneself over pain. Treatment may include deep tissue massage, internal or external, mobilization, joint manipulation, soft tissue mobilization, sensory, motor, and sympathetic and parasympathetic nerve re-training.

The cause and cure for endometriosis pain

Endometriosis is a complex disease to treat. While endometriosis excision surgery is the gold standard of treatment and does relieve a significant amount of pain, sometimes pain still lingers. There seem to be many reasons why patients are in pain and an equal amount of possible solutions to reduce pain. Dr. Shrikhande concludes by saying:

“Pain is so complex. When managing pain, it is really important to draw in a multispecialty group and work in collaboration. So many different factors play a role in a patient’s perception of pain. Regulation of stress, nutrition, diet, and exercise all play a strong role in a patient’s quality of life and the perception of their pain.”